Coral reef ecosystem collapse: Constraining rates of biological and physical erosion. Geography PhD studentship (NERC GW4+ DTP funded)

Project Background:

The growth and development of tropical coral reefs is strongly influenced both by the rate at which skeletal calcium carbonate is produced (mainly by corals), and the rate at which this carbonate is degraded or removed by biological and physical processes. The balance between these production and erosion processes is described as a reefs carbonate budget. In the Caribbean, where coral reefs have suffered severe declines in coral cover over the past few decades due to multiple human impacts and climate change, the carbonate budgets of most reefs are increasingly dominated by erosional processes. This is leading to loss of reef growth potential and structural erosion. Methodologies to quantify these carbonate budget states now exist, but whilst there is reasonably good data on rates of carbonate production to inform calculations, data on the rates at which different species erode reef material and on rates of physical removal are sparse. This PhD project aims to address these key knowledge gaps.

Project Aims and Methods:

The aim of this project is to address current data gaps relevant to constraining rates of biological and physical substrate erosion on Caribbean coral reefs, and to quantify their impacts on Caribbean reefs. This will be undertaken using a combination of field and experimental approaches, with a specific focus on the shallow-water reefs of the Mexican Caribbean in the proximity of the UNAM Lab at Puerto Morelos. Specifically, the student will: (1) undertake experiments to quantify rates of substrate erosion by endolithic sponges. This is projected to be based on ex-situ experiments, the design of which the students will take a major role in developing; (2) Assess how different sponge species utilise different substrate types and space on the reef – to inform models of changing sponge erosion rates as reef communities and substrates change; (3) Undertake experiments to quantify rates of endolithic microbioerosion between substrates/habitat spaces – to inform estimates of rates of reef-wide microborer erosion; and (4) Quantify rates of physical reef framework movement and removal – to inform predictions of rates of reef growth potential. The student is expected to have significant input into experiment design, with some flexibility to steer the key area of focus on these processes depending on individual research interests.

Candidate requirements:

Candidates must a have a good first degree (and preferably an MSc) in a relevant academic area (physical geography, ecology, earth science), a strong interest in the geomorphology or ecology of coral reefs (preferably supported by relevant field experience), good general field experience and a current SCUBA diving qualification.

Training:

The student will receive training in marine field surveying (including census-based carbonate budget assessment protocols), experimental design and in the use of a range of analytical facilities including, depending on project direction, Scanning Electron Microscopy and Micro CT scanning. In support of data collection the student will be based overseas for periods of a few weeks to months, undertaking a series of in-water and ex-situ experiments to quantify rates of microbioerosion and endolithic sponge erosion in different types of coral substrates in the Mexican Caribbean region. This work will be conducted in collaboration with Co-Supervisor Alvarez-Filip and his team.

Useful links

For information relating to the research project please contact the lead Supervisor
Prospective applicants: For information about the application process please contact the Admissions team via [Email Address Removed].